The metal door frame structure shown and described in the Day-Williams patent in addition to frame parts, includes trim parts. The frame parts are three in number, a header and two vertical jamb members all having corresponding U-shape cross-sectional configuration. The flanges of the frame parts extend upwardly and outwardly from the wall opening to extend along the wall surfaces on opposite sides of the wall. The trim parts are held by clips in such manner that the outer portions of the trim parts extend beyond the edges of the frame parts to engage the wall, thereby providing a neat finished appearance. The Day-Williams design utilizes a trim clip formed by lancing and curling metal from the frame flange itself.
Two curls result, one of which extends beyond the frame flange and is actually punched back into the frame flange itself. While the design is one of the most successful frame structures of the past ten years, maintenance of dies is believed to be a problem.
The reason is that proper operation of the dies depends upon the edge of the frame flange being in the right place for interengagement with the outer trim clip curl. This in turn depends upon the frame being made to close tolerances during roll forming operations. Of course, supplementary trimming of the frame edge could be part of the manufacturing routine, but at substantial cost.
The primary object of this invention is to provide a frame structure that is at least the equal of the successful Day-Williams design, but which does not require the frame to be made to close tolerances. Accordingly, ordinary roll forming techniques can be used, and edge trimming is not required. A companion object of the present invention is to provide a separate clip structure for trim parts that in a simple way firmly and with position accuracy, connects with the frame flange all independently of the flange edge.